Wednesday, December 3, 2008

A green and sustainable future

Club of Rome forecasts for the human future paint a dismal picture of scarcity and want, with privation leading to the collapse of civilization and mass death.

The Club of Rome view is that the future of humanity will be dismal. Yet a glance at the earth's mineral resources show that several important resources are available in great abundance, enough to make their use sustainable for the period of human habitation on the earth. The question then becomes whether there are enough of the right sort of resources to sustain an advanced materially oriented civilization over a long period of time. I intend to argue that the answer is yes.

Extracting minerals from the Earth's crust would not be possible without energy, and it is my contention that the energy present in the earth's crust in the form or Thorium, and Uranium is sufficient to last us to the end of our days as living beings on earth. Nor would it take a great deal of energy to extract thorium from the earth's crust. We have don it already in abundance and thrown it away. The World nuclear Association notes:

In Victoria, 65 million tonnes of brown coal is burned annually for electricity production. This contains about 1.6 ppm uranium and 3.0-3.5 ppm thorium, hence about 100 tonnes of uranium and 200 tonnes of thorium is buried in landfill each year in the Latrobe Valley. Australia exports 235 Mt/yr of coal with 1 to 2 ppm uranium and about 3.5 ppm thorium in it, hence up to 400 tonnes of uranium and about 800 tonnes of thorium could conceivably be added to published export figures.

Other coals are quoted as ranging up to 25 ppm U and 80 ppm Th. In the USA, ash from coal-fired power plants contains on average 1.3 ppm of uranium and 3.2 ppm of thorium, giving rise to 1200 tonnes of uranium and 3000 tonnes of thorium in ash each year (for 955 million tonnes of coal used for power generation). Applying these concentration figures to world coal consumption for power generation (7800 Mt/yr) gives 10,000 tonnes of uranium and 25,000 tonnes of thorium per year.

1200 tons of Thorium a year would be sufficient to provide the United States with all the energy it needs to power its economy. The world's fly and bottom ash mountain has already been mined, so extracting it from the earth would not require any energy. Thorium and uranium can be recovered from ash piles at highly favorable Energy Returned on Energy Invested, using acid extraction techniques. The world's economy can be operated at energy levels found now in Western Europe with the energy from 12000 tons of thorium. Thus twice the energy the world needs to assure every man woman an child on this planet a satisfactory level of material comfort is being thrown away every year in the form of thorium left in cola ash waste.

Coal ash waste is hardly the only out of ground source of now wasted thorium. Recoverable concentrations of thorium, millions of tons. are found in phosphate mine tailings, uranium mine tailings, and tin mine tailings. There is an enormous amount of Thorium in granite at a concentration that can be recovered at a very favorable EROEI. Granite used in construction and for decorative purposes in building typically has a thorium content of around 17 ppm. Thorium at that concentration is recoverable with quite favorable EROEI. Huge granite formation contain thorium at concentrations of about 50 ppm. We could supply all of the world's energy needs at abundant levels for hundreds of years without any mining. All we need to do is to recover the thorium that we now treat as waste.

I might add that Uranium is also present in recoverable amounts from the sources I have mentioned, and a Uranium based energy economy would be sustainable as well. I favor thorium because the thorium fuel cycle is more efficient than the uranium fuel cycle - efficiency as measured by its neutron economy - and hence the thorium cycle solves the problem of nuclear waste without resorting to expensive, technically difficult and potentially dangerous nuclear technology.

In 1968 the USAEC estimated the amount of thorium in the United States that could be recoverable if the price of thorium were $500 a pound to be 3 billion tons. Five hundred 1968 US dollars would be the equivalent of two thousand 2008 US dollars. Lest the reader think that this cost is extremely expensive, two thousand dollars today would buy 20 tons of coal, while the pound of thorium would containthe same amount of energy as 1500 tons of coal. Thus thorium has the potential to be a very low cost energy source.

Lowering the cost of energy from the thorium cycle would be a reason for choosing LFTR technology.

What can we do with low cost energy from thorium?

A little over a generation ago Alvin Weinberg together with H. E. Goeller set out to investigatethe Club of Rome's claims about the impending doom of human civilization. In a little noted paper, titled "Age of substitutability: or what do we do when the mercury runs out", they argued that what was needed to maintain civilization was "aninexhaustible source of energy".

They added

Most of the minerals that man uses - iron ore, carbon dioxide, and alumina - are found in nature 'in an oxidized state, or more generally, in a state of relatively hish entropy. To reduce these materials, i.e., to extract iron, to convert C02 t o cellulose, or to change alumina to aluminum, ,.. requires energy (more accurately, free energy). Thus man's economictransaction with nature involves expenditure of free energy; and as his high-grade resources dwindle, he expends more energy.

Geoller and Weinberg pointed to one "inexhaustible" sources of energy, the breeder reactor, and by breeder they were not referring to the Liquid Metal Fast Breeder, they were refeering to what they would have called the Molten Salt Breeder, that is a Liquid Fluoride Thorium Breeder reactor.

"The effect of exponential growth is to reduce the probable period of availability ofaluminum from 100 years to 31 years.''

Yet the supply of Aluminum in the earths crust was inexhaustible in human terms as can be seen above. Quoting geologist Dean F. Frasche, Geoller and Weinberg

"Total exhaustion of any mineral resource will never occur. Minerals, and rocks that are unexploited will always remain in the earth's crust. The basic problem is how to avoid reaching a point where the cost of exploiting those mineral deposits which remain will be so costly, due to depth, size, or grade, that we cannot produce what we need without completely disrupting our.socia1 and economic structures."

There would be three stages of progressively greater resource scarcity, Geoller and Weinberg argued.

In Stage one, our present patterns of non-renewable resources would continue, but would run its course sometime between 2005 and 2025.

In Stage two fossil fuels would be increasingly exhausted, and the use of more exotic metals would decline with steel alloiys playing an increasingly important role.

In Stage II fossil fuels would be exhausted and the material basis of society would rely on inexhaustible resources.

In Stage III, inexhaustible resources will be substituted for exhausted resources.

insofar as limits to mineral resources can be discerned, the condition of life in Stage 111, the Age of Substitutability, will not be drastically different from our preserlt condition of life: we have the physical possibility of living in the Age of Subititutability without "completely disrupting our social and economic structure". To reach this state without immense social disruption will, however, require unprecedented foresight and planning.

They add

Let 'us now state the Principle of "Infinite" Substitutability: with two notable exceptions - phosphorous and energy-producing fossil fuels, i.e, CH, the society can subsist with relatively little loss of living standard on infinite or near-infinite minerals. Such a civilization would be based largely on glass, plastic, wood, cement, iron, aluminum, and magnesium: whether it will be anything like our present society will depend upon how much of the ultimate raw material , energy, we can produce - and how much energy will cost, both economically and environmentally.

Thus a high standard of living is possible for all people on earth with the long term resources that humans will have at their disposal over the millions of years. There are however, implications for agriculture:

With regard to the trace elements 'which are present in the soils and are needed only at low concentrations, modern agriculture slowly depletes soil of these elements. In the near term, shortages can undoubtedly be supplied from inorganic sources; in the long run, we will be forced to return agricultural and animal wastes to the soil, particularly for the trace elements with limited resources such as copper, zinc, and cobalt.

The gap between preferred materials and available resources thus can be resolved in two ways:1. By recycling2. By substitution.

The survival of Civilization would not be sustainable without be possible without unlimited energy, and As I have already pointed out Alvin Weinberg believed that the best source of sustainable would be found in the use of the thorium fuel cycle, in the Liquid Fluoride Thorium Reactor.

Tomorrow I hope to explain why, in Weinberg's view, the LFTR was greener than the Sun.

5 comments:

Anonymous
said...

As the most energetic and articulate advocate of thorium power, it is important that your arguments to the proponents of solar and wind power be further perfected. In this spirit, take the following criticisms and suggestions kindly.

This post touches on an important and fatal vulnerability of the environmentalists, that is the impossibility of solar or wind power to support an industrial based society.

The amount of fossil based power that is consumed by our current industrial base is at least as great as that consumed by electrical power generation. The production of steel, plastic, aluminum, cement, paper, and so on, all the stuff of our everyday lives, not to mention the electrical power consumed by industry, far outpaces power usage of the retail customer.

Industry is highly centralized, sized, and concentrated to take advantage of economies of scale and short transportation lines. Over the years, they have located near the natural resources used in those plants and rivers that can carry bulk industrial commodities. This region, the rust belt, is not near solar resources of the desert or the wind corridors of the open planes in the mid west.

Vast planes of solar panels or a forest of wind mills driving a blast furnace is a ridicules concept on its face.

The rust belt has already been sacrificed to our industrial economy; its rehabilitation will be enormously expensive and its relocation to the virgin desert or the open and wind swept prairies of the mid west is unthinkable. The unspoken agenda of the environmentalists is to relocate the blast furnesses, the glass ovens, and the cement plants to China and India where they are out of sight and out of mind; the polluted and smoky air slowly killing some other peoples at a rock bottom labor rates.

But the CO2 still is produced and in the end still does its damage. Think about this, formulate an air tight argument that will expose the ridiculously dangerous intentions of these nuvo primitivists in their quest to reenter the caves of the noble savage in a depopulated world.

Their belief that modern society is moving away from its traditional roots, losing touch with its "true primitive condition" has only tragedy in its consequence. Expose them when you can for the good of those to come.

Thank you for the comments and compliment. My approach has been to investigate solutions sector by sector, with transportation and electricity my primary focus. I have also given some attention to space and water heating. I am aware of the process heating, I am also aware of some of the limitations of molten salt and pebble bed technology. At the moment neither is capable of providing the heat needed in the manufacture of cement, for example. It may be that high temperature gas cooled reactors will do thew trick, but I have not looked at that yet. There would be many material issues in generating that sort of heat with a reactor. Of course it has to be done, and our national government as yet to see that. Thank you for your awareness.

Charles, I agree about the amount of Th available...it's a geological fact. But the process of refining it from coal fly ash is very expensive...even if the energy were free. Yes, the Chinese and a US company in partnership have a pilot project to produce yellow-cake for the huge concentrated amounts the Chinese have laying around everywhere. And yes, probably Th is a byproduct of *this* refining...but we have that 500,000 tons of double-digit concentration up there in Idaho way...why all the focus on harder methods?

There is a rhetoric aspect to the coal arguement. I have no doubt about there being chraper sources of thorium. The argument that there is more energy in the tiny thorium content of coal that can be extracted from burning the coal is also a little bit of a joke.